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  1. #11
    joeyk49's Avatar
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    Quote Originally Posted by 127
    A neuron either fires or doesn't... A 1 or a 0. There are lots of them, an they don't work sequentially but they're esentially either on or off.

    A bit like a silver halide crystal - it either get's developed or it doesn't - thats a 1 or a 0 too... (but there are lots of them arranged more inteligently than in a digital sensor).

    Ian
    Contrary to conventional wisdom, I find that my neurons fire much better after one or two pints!

  2. #12

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    Quote Originally Posted by 127
    A neuron either fires or doesn't... A 1 or a 0.
    Ian
    That's wrong, plain and simply false, and besides the brain has massive redundancy and similitude. It is not serial, nor even parallel. If you want to hunt for a metaphor, you might look to 'concensus' for how the brain works, but not in the digital way.

    In any age people use what they think is familar to make metaphors. The brain is not earth, wind, fire, a steam-engine, or a godness, and it sure as hell ain't digital.

  3. #13

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    Quote Originally Posted by joeyk49
    Contrary to conventional wisdom, I find that my neurons fire much better after one or two pints!
    Contrary to Contrary, a health condition known as Essential Tremor (ET) is more responsive to moderate amounts alcohol with fewer side effects than modern medicines. I kid you not.

  4. #14
    127
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    Quote Originally Posted by jjstafford
    That's wrong, plain and simply false....
    "A neuron operates by receiving signals from other neurons through connections, called synapses. The combination of these signals, in excess of a certain threshold or activation level, will result in the neuron firing, that is sending a signal on to other neurons connected to it. "

    http://www.cheshireeng.com/Neuralyst/nnbg.htm


    "When a neuron sends an excitatory signal to another neuron, then this signal will be added to all of the other inputs of that neuron. If it exceeds a given threshold then it will cause the target neuron to fire an action potential, if it is below the threshold then no action potential occurs."

    http://www.mindcreators.com/NeuronBasics.htm

    A neuron either fires or it doesn't. Just because there are lots of them, connected in interesting ways doesn't change that. The operation is nothing like a computer, but it's still based on a firing/not firing binary mechanism.

    Ian

  5. #15
    Ed Sukach's Avatar
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    Quote Originally Posted by 127
    "A neuron operates by receiving signals from other neurons through connections, called synapses. The combination of these signals, in excess of a certain threshold or activation level, will result in the neuron firing, that is sending a signal on to other neurons connected to it. "
    http://www.cheshireeng.com/Neuralyst/nnbg.htm
    I, too, was taught that neurons either fire or they don't - no "analog" quality.
    Not why I am commenting, though ... The information on that web site is interesting .. except for the "Speed of light in a wire is about 200,00 meters per second - about 2/3rds of the speed of light in - did it say "free air"? - if it did, that should have been "In a vacuum".
    However - the "Speed of light in a wire"??? Light has a hell of a lot of trouble getting though a metallic wire. Possibly the writer meant to say "The speed of electricity in a wire ..?"

    Enough. This constitutes my nit-picking quota for the day.
    Carpe erratum!!

    Ed Sukach, FFP.

  6. #16

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    Quote Originally Posted by 127

    "When a neuron sends an excitatory signal to another neuron, then this signal will be added to all of the other inputs of that neuron. If it exceeds a given threshold then it will cause the target neuron to fire an action potential, if it is below the threshold then no action potential occurs."

    http://www.mindcreators.com/NeuronBasics.htm

    A neuron either fires or it doesn't. Just because there are lots of them, connected in interesting ways doesn't change that. The operation is nothing like a computer, but it's still based on a firing/not firing binary mechanism.

    Ian
    The firing threshhold varies according to local chemical concentrations so the transmitted signal is binary, but there are analogue controls and feedback.

  7. #17

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    Ian, I appreciate what you are pointing out, however the firing of any synapse is negotiated by other principles which are overwhelmingly more numerous and entirely analog. Look to the way molecules work by mechanical (topograhical) fittings, for example, and when an author writes that a synapse 'fires' electrically, the author is using an inappropriate metaphor; the physics are not the same as light/electrical wave radiation. Our nerves are not fiber-optical. Wow - if they were... but I digress.

    Finally, there is so much more yet to understand, and so far it is all analog except perhaps for one truly intriguing theory that brain cells (in concert) exploit the structure of micro-tubules to achieve quantum-mechanical effects - and that's not digital either; not by a long shot. This is not kook science, but a theory of probably the finest physicist/mathematician alive today, Sir. Roger Penrose.

    Enough. I need coffee and rest. (Honestly, once I get out of this temporary physical invalid state I won't spew off at the fingers as much.)

  8. #18
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    Quote Originally Posted by Ed Sukach
    "Speed of light in a wire"??? Light has a hell of a lot of trouble getting though a metallic wire. Possibly the writer meant to say "The speed of electricity in a wire ..?"

    Enough. This constitutes my nit-picking quota for the day.
    My turn !

    Shouldn't it have said "the speed of electromagnetic radiation in a wire?" Visible light, electricity, and radio signals, as well as infrared and ultaviolet light and nuclear radiation are all forms of electromagnetic radiation and travel at the same speed...in a vacuum...I think...

    Has this ever happened to you? You and a buddy are trying to remember the name of a band you heard on the radio and it's just killing you, because you're soooo close to remembering it. Finally you give up. Hours after giving up, with no warning and without even thinking of it again, the name of the band pops into your head! Your brain, independent of your conscious you, remained at the task and beligerently kept chewing away at the problem...freaks me out every time!!

    Murray

  9. #19

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    My head hurts .....
    Graeme Hird
    www.scenebyhird.com

    Failure is NOT an option! It comes bundled with your software ....

  10. #20
    joeyk49's Avatar
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    Things were much easier when I played with a pair of coffee cans and a string...the speed of light transmuted through twisted hemp cord and reproduced in the Maxwell House index thermocoupled receiver never ceased to amaze me.

    Or was it Chock Full O Nuts???

    No worries about email viruses then, either...

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